During the years, Immel has been a regular sculptor and special effects makeup artist for the K.N.B. Effects Group, a special effects company owned by Robert Kurtzman, Gregory Nicotero and Howard Berger which also worked on Star Trek Nemesis. Among the projects he worked on for this company are the horror sequel Jason Goes to Hell: The Final Friday (1993, with Wayne Toth and Ron Pipes), the science fiction film DNA (1997, with Wayne Toth), Rob Bowman's mystery film The X-Files (1998, with Don Lanning), the horror thriller The Haunting (1999, with Wayne Toth), the mystery drama The Green Mile (1999), John Carpenter's horror film Ghosts of Mars (2001), the thriller Vanilly Sky (2001), the science fiction comedy Spy Kids (2001), Joss Whedon's science fiction film Serenity (2005), the fantasy movie The Chronicles of Narnia: The Lion, the Witch and the Wardrobe (2005), the action thriller Planet Terror (2007), and the horror thriller The Unborn (2009).

Other projects Immel worked on as special effects makeup artist include the horro film Scream (1996) and its sequel Scream 2 (1997), the drama Boogie Nights (1997), the horror thriller House on Haunted Hill (1999, with David Abbott, Diane Pepper, Faith Vecchio, Patricia Vecchio, Shannon Shea, and Alan Tuskes), the war drama We Were Soldiers (2002), the comedy sequel Austin Powers in Goldmember (2002), the crime thriller Sin City (2005), the fantasy adventure Pirates of the Caribbean: Dead Man's Chest (2006) and its sequel Pirates of the Caribbean: At World's End (2007), and J.J. Abrams' science fiction thriller Cloverfield (2008, with Jake Garber, Brad Look, and Veronica Lorenz).